| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption even in a state that an AC power source is received while being interlinked with the sleep mode of a notebook personal computer in an AC adaptor.SOLUTION: An AC adaptor includes: a feedback circuit constituted of a switching power source for applying an input power to the primary coil of a transformer, and for turning on/off a switching element connected to the primary coil of a transformer by a control circuit to induce a pulse voltage in the secondary coil of the transformer, and for supplying an output voltage obtained by rectifying and smoothing the pulse voltage via a DC plug to a load, and configured to feedback the output voltage to the control circuit to set a predetermined voltage; and a circuit for performing the start/stop of the output voltage in accordance with a signal from a load device via the DC plug, and for decreasing the output voltage to a voltage which is less than a rated voltage. The load device and the switching power source include an authentication circuit for performing inter-device authentication in accordance with a digital signal via each DC plug, and the DC plug is constituted of three cables, and the start/stop or voltage variation of the output voltage is performed in accordance with a DC signal from the load device. |
